Test/Measurement Host Tuning

Here is a quick reference guide for tuning settings for Linux Test/Measurement hosts such as perfSONAR hosts that run tools such as bwctl, iperf or nuttcp. Note that we are assuming the measurement tools are attempting to perform serialized single stream TCP tests with the BWCTL tool. This assumption means we have increased the base TCP socket sizes to support larger memory allocations, and that parallel stream use is not as common as it would be for a tool such as GridFTP. For help in learning the approproate size of the socket, you can use the BDP calculator.

To support 10Gbps speeds, on paths of 100ms, 120MB of buffer must be available. You may want to adjust these values depending on the latency of the paths you want to test. Hosts configured to use jumbo frames need more buffer space as well.